Establishment of rat subarachroid hemorrhage model by second injection of blood into cisterna and protective effect of nimodipine on brain

Objective To establish rat model fit to study cerebral vasospasm(CVS) induced by subarachnoid hemorrhage(SAH).Methods Wistar rats were divided into sham operation group(injected with of 0.3 mL saline into the magnum pool),SAH model group(injected with 0.3 mL no anticoagulation autologous blood into the cisterna magna),SAH nimodipine treatment group(injected introperitoneally with 0.2 mg·kg-1 nimodipine 30 min after modeling and every day after operation).The neurological deficits of rats and incidence of decreased food intake were observed and the largest rat basilar artery blood flow velocity(Vmba) was detected with transcranial Doppler(TCD) at the 1st,7th,14th and 21th after operation.Results Compared with sham operation group,the basilar artery blood flow,nerve dysfunction and decreased food intake(including 2 to 4) in SAH model group were consistent with the occurrence of schedule,mainly increased at the 1st day,peaked on day 7,decreased on day 14,normal on day 21,and the mortality rate was 0.Compared with SAH model group,the basilar artery blood flow velocity in treatment group was decreased,the incidence of nerve dysfunction and decreased food intake were decreased also.Conclusion Through the second injection of blood into cisterna magna,a rat model closing to clinic and fiting for research on CVS induced by SAH is established,and nimodipine can significantly reduce the degree of CVS after SAH.